(1) Field of the Invention
This invention relates to a one-way sprag clutch, and more specifically to a retainer for a way sprag clutch. This invention is also concerned with a method for the assembly of sprags in a retainer.
(2) Description of the Prior Art
In a one-way sprag clutch (hereinafter abbreviated as "OWC" for the sake of brevity), it has conventionally been practised to form windows, i.e., through-holes in a metal retainer and then to insert and maintain sprags in the through-holes.
Since the through-holes have dimensions slightly larger than the angular and axial dimensions of the sprags, the sprags are allowed to pass easily through the through-holes. This feature is convenient for the assembly of the retainers but is accompanied by a problem that the thus-assembled sprags may slip out from the retainer.
As a method for solving the above problem, such sprags have conventionally been prevented from slipping out by means of a spring member having a relatively special shape and made of a special material, such as ribbon spring, because the use of such a retainer alone is insufficient.
It is however the primary function of the spring member to apply a raising moment to the sprags in a direction such that the sprags are brought into engagement with an inner and outer races. When it is desired to remove the sprags from the thus-assembled OWC, the sprags can be removed from the retainer by bending the spring member.
This means that cumbersome, time-consuming and costly handling is required upon assembly, packing and shipping of an OWC and its assembly in a machine and the manufacturing cost of the machine is thus increased.
Where a ribbon spring is supposed to have an additional function to prevent the drop-off of sprags, unavoidable limitations are imposed on the shape of the ribbon spring so that a smaller degree of designing freedom is only available upon making the ribbon spring perform the above-mentioned principal function thereof, namely, upon allowing the ribbon spring to produce a dragging torque sufficient to bring the inner and outer races into engagement.